Preclinical investigation has shown the role for endogenous opioid system in the regulation of eating. Naloxone, an antagonist, has been shown to reduce eating and food consumption. This study was designed to attempt to correlate plasma in anorexic, bulemia, and control subjects. We have been able to measure naloxone concentration in 5 subjects using a sensitive HPLC method that employs electrochemical detection. We are in the process of collating data before performing correlation analysis.